In vehicles, heaters operated with hydrocarbon fuel are used as parking heaters or auxiliary heaters to heat various areas of a vehicle, especially a vehicle interior. The functionality as an auxiliary heater is also becoming increasingly necessary in internal combustion-driven vehicles since modern combustion engines no longer provide sufficient heat for heating the vehicle interior because of the comparatively high efficiency. In vehicles operated with an electric motor, practically no waste heat forms in the drive unit itself, such that the heat energy needed for heating the vehicle interior can be produced by an additional heater, for example, one operated with hydrocarbon fuel.